Configurable prober for TFT LCD array test

ABSTRACT

An improved prober for an electronic devices test system is provided. The prober is “configurable,” meaning that it can be adapted for different device layouts and substrate sizes. The prober generally includes a frame, at least one prober bar having a first end and a second end, a frame connection mechanism that allows for ready relocation of the prober bar to the frame at selected points along the frame, and a plurality of electrical contact pins along the prober bar for placing selected electronic devices in electrical communication with a system controller during testing. In one embodiment, the prober is be used to test devices such as thin film transistors on a glass substrate. Typically, the glass substrate is square, and the frame is also square. In this way, “x” and “y” axes are defined by the frame. The electrical pins may be movable along the axial length of the prober bars, or may be selectively pushed down to contact selected contact pads on the substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of co-pending U.S. patentapplication Ser. No. 10/889,695, filed Jul. 12, 2004. The '695 patentapplication is entitled “Configurable Prober for TFT LCD Array Test.”

The '695 patent application claims benefit of and is acontinuation-in-part of co-pending U.S. patent application Ser. No.10/778,982, filed Feb. 12, 2004. That application is entitled “ElectronBeam Test System with Integrated Substrate Transfer Module.” Thatapplication is incorporated herein in its entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention generally relate to testing systemsfor electronic devices on substrates. In addition, embodiments of thepresent invention generally relate to an improved prober for conductinga thin film transistor liquid crystal display array test on a variety offlat panel substrate designs.

2. Description of the Related Art

Active matrix liquid crystal displays (LCDs) are commonly used forapplications such as computer and television monitors, cell phonedisplays, personal digital assistants (PDAs), and an increasing numberof other devices. Generally, an active matrix LCD comprises two glassplates having a layer of liquid crystal materials sandwichedtherebetween. One of the glass plates typically includes a conductivefilm disposed thereon. The other glass plate typically includes an arrayof thin film transistors (TFTs) coupled to an electrical power source.Each TFT may be switched on or off to generate an electrical fieldbetween a TFT and the conductive film. The electrical field changes theorientation of the liquid crystal material, creating a pattern on theLCD.

In order to provide quality control for thin film transistors on a largearea glass substrate, it is desirable to conduct a liquid crystaldisplay “array test.” The array test allows a TFT LCD manufacturer tomonitor and correct defects in the pixels during processing. A knownmethod of testing pixels is known as electron beam testing, or “EBT.”During testing, each TFT is positioned under an electron beam. This isaccomplished by positioning a substrate on a table positioned below thebeam, and moving the table in “x” and “y” directions to sequentiallyposition each TFT on the substrate below the electron beam test device.One such device which enables flat panel display fabricators to testdevices formed on flat panels is a PUMA™ electron beam tester availablefrom AKT, Inc., a subsidiary of Applied Materials, Inc. located in SantaClara, California.

In order for the LCD array test to be conducted, a “prober” is used. Atypical prober consists of a frame that usually covers the entiresubstrate under investigation. The frame has a plurality of electricalcontact pins thereon at locations that match the contact pads of thesubstrate. Electrical connection to the pins is accomplished by finewire connections to an electronics driver board. The board is usuallysoftware controlled.

In operation, the substrate is raised into contact with the prober. Morespecifically, the contact pads of the substrate are placed into contactwith the electrical pins of the prober. The contact pads, in turn, arein electrical communication with a pre-defined set of the thin filmtransistors, or “pixels.” An electrical current is delivered through thepins and to the contact pads. The current travels to and electricallyexcites the corresponding pixels. An electron beam senses voltages inthe excited pixels in order to confirm operability of the various thinfilm transistors on the substrate.

In the past, each prober has been custom made for a particular displaylayout design. This means that each electrical device and substratelayout has required a different prober frame having the matchingconfiguration for the device array. The result is that the purchaser ofsemiconductor fabrication machinery must also purchase a uniquelycompatible prober in order to test the fabricated pixels.

Modification of an individual prober for a new device layout isexpensive. Therefore, it is desirable to provide a prober that isconfigurable to match a different substrate sizes and different devicelayouts. It is also desirable to provide a prober that can befunctionally adjusted for different display layouts or arrangements.

SUMMARY OF THE INVENTION

The present invention generally provides an improved prober for anelectronic devices test system. The prober operates to test electronicdevices such as pixels on a substrate. The prober is “configurable,”meaning that it can be adapted for different device layouts, differentdisplay arrangements, and different substrate sizes. In one embodiment,the prober includes a frame. The frame receives at least one adjustableprober bar having a first end and a second end. A frame connectionmechanism is provided that allows for attachment of the prober bar tothe frame at selectable points along the frame. The prober also includesa plurality of electrical contact pins, or “probe pins,” along theprober bar. The probe pins contact selected test pads on the substratein order to place electronic devices on the substrate in electricalcommunication with a system controller during testing.

Probe pins are also placed along the prober bars. In one aspect, theprobe pins are integral to the prober bars, meaning that they have afixed axial position relative to the bars. In another embodiment,however, the probe pins are part of separate bodies referred to hereinas “probe heads.” The probe heads are movably attached to correspondingprober bars along the axial length of the bars. In this way, theposition of the probe pins within the probe frame can be furtheradjusted for testing of different display sizes and device layouts. Instill a different embodiment, multiple probe pins are disposed on fixedprobe heads along the length of the prober frame. This permits theoperator to select which probe pins to actuate in accordance with thelocation of the contact pads on a substrate.

Typically, the prober will be used to test devices on a glass substratehaving multiple displays. Preferably, each of the electronic devices isa thin film transistor. Typically, the glass substrate and the frame areeach rectangular or square. In this way, “x” and “y” axes are defined bythe frame. In one aspect, the at least one prober bar is placed on theframe along the “y” direction, serving as a “y” bar.

In one arrangement, the frame has four sides representing two opposingsides. In addition, the frame connection mechanism may define aplurality of holes along an inner surface of the four sides of the framefor receiving the first and second ends of the prober bars,respectively. In one embodiment, each prober bar includes an end cap ateach of the first and second ends, with each end cap configured to beattached to selected holes of the frame connection mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1 presents a perspective view of a configurable prober, in oneembodiment. The prober is part of an electronic devices test system. Theprober is positioned on a test system table that moves the prober in “x”and “y” directions.

FIG. 2 is a cross-sectional view of an illustrative test system table. Aprober is shown schematically on the table. In addition, electron beamtest columns are seen over the prober. A substrate is placed between thetest table and the prober.

FIG. 3 shows the test system table of FIG. 2. In this cross-sectionalview, the substrate has been raised in the “z” direction into electricalcontact with the prober.

FIG. 4 presents a schematic view of a configurable prober, in oneembodiment. Prober bars are shown within a universal frame in the “y”direction.

FIG. 5 provides a perspective view of a prober bar oriented along the“x” axis, with an end cap at an end of the prober bar. The end cap isreleasably connected to the frame.

FIG. 6 shows the end cap of FIG. 5 exploded away from a prober bar.

FIG. 7 is a partial exploded view of the prober of FIG. 4. The prober isabove the base for the device testing system. Controller pads for thetesting system are seen.

FIG. 8 provides a further enlarged and exploded view of the electricalconnection between the prober and the base for the device testingsystem.

FIG. 9 presents a bottom view of an exemplary prober bar. A plurality ofelectrical contact pins are seen extending from the prober bar.

FIG. 10 provides a plan view of a prober in an alternate arrangement.Multiple prober bars are shown within a configurable prober frame.

FIG. 11 illustrates the prober bars of FIG. 10 positioned over alarge-area glass substrate for testing.

FIG. 12 shows the prober bars and probe heads reconfigured for differentdisplay layouts.

FIG. 13 is a plan view of an alternate embodiment of a prober.

DETAILED DESCRIPTION

The present invention generally provides an improved prober for anelectronic devices test system. For purposes of this disclosure, theterm “test system” means any system that may be used to test electronicdevices on a substrate. Such a test system may include opticalinspection systems, electron beam test systems, systems that detectcolor changes, and others. The prober for the electronic devices testsystem is “configurable,” meaning that it can be adapted for differentdevice layouts and substrate sizes.

FIG. 1 presents a perspective view of a configurable prober 400, in oneembodiment. The prober 400 is part of an electronics device test system100. In one embodiment, the prober 400 is part of an electron beam testsystem 100, though other systems could be used. The prober 400 ispositioned on a test system table 110 that moves the prober 400 in atleast “x” and “y” directions. In the arrangement of FIG. 1, the table110 defines a tubular frame fabricated from stainless steel. However,the scope of the present inventions is not limited by the configurationor material of the table 110. An optional cable carrier 116 is providedexternal to the table 110.

The table 110 supports various plates 120, 130, 140 that translate theprober 400 in different dimensions. The three plates 120, 130, and 140are planar monoliths or substantially planar monoliths, and are stackedon one another. The three stacked plates are seen in cross-section inFIG. 2, which is a cross-sectional view of the illustrative test system100 of FIG. 1.

In one aspect, each of the three plates 120, 130, 140 is independentlymovable along orthogonal axes or dimensions. The first plate supportsthe second 130 and third 140 plates, as well as the prober 400. Thefirst plate moves the supported second 130 and third 140 plates along a“y” axis. FIG. 1 shows bearing surfaces 122, for moving the first plate120. The linear bearing surfaces 122 are provided in the “y” axis forthe first plate 120.

The second plate 130 supports the third plate 140, and moves the thirdplate 140 and prober 400 in an “x” axis. Linear bearing surfaces 132 areprovided along the “x” axis for the second plate 130. The second plate130 supports the prober 400 through a collar 135.

Finally, the third plate 140 supports the substrate. A substrate isshown at 150 in FIGS. 1 and 2. The third plate 140 moves the substrate150 in a “z” axis. More specifically, the third plate 140 lifts thesubstrate 150 into contact with pogo pins (shown at 480 in FIG. 9) ofthe prober 400.

As indicated, a substrate 150 is shown in FIGS. 1 and 2. Theillustrative substrate 150 is a large area glass substrate that containsa plurality of conductive electronic devices. An example is a pluralityof thin film transistors (TFT's). It is understood that the TFT's arequite small and will not be visible in the perspective view of the testsystem 100.

It is also understood that the test system 100 contains numerous otherfeatures and components. Where the test system is an electron beam testsystem, the system 100 may include a prober transfer assembly, a loadlock chamber, a testing chamber and, optionally, a prober storageassembly, for example. The testing chamber will have electron beamcolumns for directing electron beams down onto the pixels underinspection. These various features are not shown in FIG. 1; however,electron beam columns are seen at 200 in the cross-sectional view ofFIG. 2. Details of an exemplary electron beam test system containingsuch features are disclosed in the pending U.S. Patent Applicationentitled “Electron Beam Test System with Integrated Substrate TransferModule.” That application was filed on Feb. 12, 2004, and bears Ser. No.10/778,982.

Referring again to FIG. 2, a cross-sectional view of the illustrativetest system 100 of FIG. 1 is presented. The test system 100 againincludes a test system table 110. The table 110 supports the first plate120, the second plate 130, and the third plate 140. The first (or lower)plate 120 and the second (or intermediate) plate 130 each move linearlyalong a horizontal plane, but move in a direction orthogonal to oneanother. In contrast, the third (or upper lift) plate 140 moves in avertical direction or the “z” direction. Plates 120, 130 are driven by alinear motor or other actuator. Linear actuators such as linear motorsor hydraulic cylinder-and-piston arrangements (not shown) may beprovided for translating the plates 120, 130.

The prober 400 is shown schematically on the table 110, supported by theplates 120, 130, 140. The plates 120, 130, 140 selectively translate theprober 400 in different dimensions. In the illustrative system 100, theprober 400 may be moved in “x,” “y” directions. Operation of the testsystem 100 in order to move the prober 400 is described in the pending'982 Patent Application entitled “Electron Beam Test System withIntegrated Substrate Transfer Module.” As noted above, the pending '982application is referred to and incorporated by reference herein to theextent its disclosure is not inconsistent with the present disclosure.FIG. 2 is a duplication of FIG. 5 from the pending '982 application. Forthis reason, discussion of the system 100 shown in FIG. 2 herein islimited.

It should be noted that the test system 100 further includes an endeffector 170. A portion of the end effector is shown in cross-section inFIG. 2. The end effector 170 transfers the substrates 150 in and out ofthe testing chamber. In operation, the end effector 170 may be extendedfrom the testing chamber into an adjoining chamber or system such as aload lock chamber (not shown) to load a substrate. Likewise, the endeffector 170 having a substrate loaded thereon may be extended from thetesting chamber into the load lock chamber to transfer the substrate 150to the load lock chamber. A motion device, such as a linear actuator, apneumatic cylinder, a hydraulic cylinder, a magnetic drive, or a stepperor servo motor, for example may be coupled to the end effector 170 toassist this transfer. In one aspect, the end effector 170 includes apair of bearing blocks 172 that permit the end effector 170 to move intoand out of the testing chamber. Additional features of the end effectorand the transfer of substrates are provided in the '982 PatentApplication.

The end effector 170 cooperates with the third plate 140 duringsubstrate transfer. In this respect, the third plate contains one ormore z-axis lifts 142 coupled to the plate 140. Each z-axis lift 142 isdisposed within a channel 146. A bellows 148 is arranged about each lift142 to reduce particle contamination within the testing chamber. Thez-axis lift 142 moves up and down vertically and may be actuatedpneumatically or electrically. The bellows 148, in turn, compress andexpand in response to the movement of the corresponding lifts 142. Inthe view of FIG. 2, the upper lift plate 140 is in its lowered position.The substrate 150 is resting on pins 125 on the “x” plate 130.

The illustrative test system 100 of FIG. 2 also shows electron beamtesting (EBT) columns 200. In this view, one pair of columns 200 isshown. However, there will typically be two (or possibly more) pairs ofEBT columns. The EBT columns 200 are disposed on an upper surface of achamber housing 105 and are attached to the housing 105. The housing 105provides a particle free environment and encloses the prober 400 andtable 110.

FIG. 3 shows the test system 100 of FIG. 2 in a test position. Here, thez-axis lift 142 has been actuated to raise the substrate 150. It can beseen that the substrate 150 has been raised into contact with the prober400. More specifically, contact is made between the substrate 150 andpogo pins (not shown) on a bottom face of the prober 400. It isunderstood that in other test systems, the prober may instead by loweredinto contact with the substrate; the present inventions are not limitedas to the manner in which contact is achieved.

Moving now to FIG. 4, FIG. 4 presents a schematic view of a configurableprober 400, in one embodiment. The prober 400 has a frame 410. In theembodiment of FIG. 4, the frame 410 is a polygonal frame having foursides. In this particular arrangement, the frame is square, though otherconfigurations may be provided such as rectangular. The frame 410defines “x” and “y” directions or “axes.”

The prober 400 also includes one or more prober bars 420. In the view ofFIG. 4, three separate prober bars 420 are shown within the frame 410;however, other numbers of prober bars 420 may be employed. Each of theseprober bars 420 is positioned at a selected coordinate along the “x”axis, and is parallel to the “y” axis. In this orientation, the proberbars 420 are “y” prober bars. The areas defined between the prober bars420 form test areas 450 (also shown in FIG. 7).

The position of the prober bars 420 along the frame 410 may be changed.In this respect, the connection between the respective prober bars 420and the frame 410 is releasable and relocatable. To provide for thisfeature, a frame connection mechanism 412 is provided that allows forready relocation of at least one prober bar 420 to the frame 410 at aselected coordinate along the “x” or “y” axes of the frame. In oneembodiment, the frame connection mechanism 412 is a plurality ofthrough-holes placed along or formed within the inner surface of theframe 410. Exemplary through-holes are shown at 414 in the enlarged viewof FIG. 5. The through-holes 414 receive end caps 440 placed at opposingends of the prober bars 420 which form part of the frame connectionmechanism 412 as well.

FIG. 6 provides a perspective view of an end cap 440. The end cap 440 isexploded away from an end of a prober bar 420. The end cap 440 includesone or more connecting members 444 for connecting to the frameconnection mechanism 412 of the frame 410. In the end cap 440arrangement of FIG. 6, a pair of bolts is provided as the connectingmembers 444. The end cap 440 also has a channel 442 for receiving ashoulder 431 on the prober bar 420. An optional bolt 446 is provided inthe channel 442 of the end cap 440. The bolt 446 is configured tothreadedly connect to the prober bar 420 through a threaded opening (notshown) formed on the prober bar 420.

In order to relocate a prober bar 420 along the frame 410, the bolts 444are backed out of the holes 414 of the frame 410, and then advanced intodifferent holes 414 located along the frame 410. In this manner, theposition of the prober bars 420 along the “x” axis of the frame 410 maybe adjusted. This, in turn, permits the user to employ the same prober400 for different substrate sizes and for different deviceconfigurations.

In accordance with the present invention, prober bars 420 may also bepositioned in the “x” direction of the prober frame 410, meaning thatthe prober bars are oriented parallel to the “x” axis. FIG. 5 providesan enlarged perspective view of a prober bar 430, with an end cap 440 atan end of the prober bar 420. The end cap 440 is again connected to theframe connection mechanism 412 of the frame 410. In this orientation,the prober bar is an “x” prober bar labeled as 430, and can be moved toa different position along the “y” axis. If the dimensions of the frame410 are different in the “x” and “y” directions, then the lengths of the“x” and “y” prober bars 430, 420 will also be different.

As an additional option, “x” prober bars 430 may be placed between “y”prober bars 420, or between a “y” prober bar 420 and the frame 410. Insuch an arrangement, a substantially shorter “x” prober bar would beemployed.

As an additional option, the frame connection mechanism 412 may beadapted to position a prober bar 420 between through holes 414. Forexample, the end cap 440 may have different channels for incrementallyre-positioning the bar 420 laterally. This permits fine tuning of thelateral position of the “y” prober bar 420 along the “x” axis.

FIG. 7 provides a perspective view of the prober 400 of FIGS. 1 and 4 aspart of a test system 100. It can be seen that the prober 400 has aplurality of electrical connection pads 472. The pads 472 are configuredto place the frame 410 in electrical communication with a systemcontroller (not shown) of the testing system 100. Each of the pads 472has a plurality of “frame” pins 470 (seen more clearly in FIG. 8). Pads472 are aligned with mating pads 128 on the intermediate “x” plate 130.The mating pads 128 include printed circuit boards that interface withthe controller for the testing system 100. The pads 128 receiveelectrical signals that come from the controller and deliver them to theconnected prober electrical connection pads 472. The detachable pin470—pad 128 connection allows the prober 400 to be removed from the testsystem 100 for microscope operations and servicing.

It should be noted that the through-holes 414 in the frame 410 of FIG. 7are not visible, as a cover has been temporarily placed on the proberframe 410. The cover is used during testing to shield the wires (notshown) that travel from the probe pins (shown at 480 in FIG. 9, anddiscussed below) to the printed circuit board 128. Without the cover,there is the potential that the E-Beam column 200 will charge up thewires. However, a cable channel for electrical connections is seen at416 in FIG. 7.

FIG. 8 provides a further enlarged view of the prober 400 of FIG. 7. Inthis view, the electrical connection between the prober frame 410 andthe test system 100 is more clearly seen. In this respect, electricalframe connection pads 472 are seen aligned over test system pads 128. Inaddition, an alignment pin 461 is seen at a corner of the prober frame410. The alignment pin 461 is tapered so as to be guided into a locatingseat 462 provided in the upper “x” plate 130. Bolts (not seen) securethe locating seat to the upper “ye” plate 140.

The frame electrical connection is done in such a way as to allow for awide range of possible display layouts, such as from 25 to 1 display persheet, and from 14″ to about 50″ display. More generally, the electricalconnection is configurable for any display configuration that the proberframe size will accommodate.

The prober 400 also has a plurality of electrical contact pins, referredto as probe pins 480. One type of probe pin 480 is a pogo pin. The probepins 480 are placed along each of the prober bars 420, 430. FIG. 9presents a bottom view of an exemplary prober bar 430. A plurality ofelectrical probe pins 480 are seen extending from the prober bar 430.While the probe pins 480 are shown along an “x” prober bar 430, it isunderstood that pogo pins would also be used for a “y” prober bar 420.

The probe pins 480 may be selectively configured during initial probersetup. The probe pins 480 may be press-fit into holes along the proberbars 420. In the prober arrangement 400 of FIG. 4, the pins 470 areintegral to the prober bars 420. In this respect, the prober 400 is“semi-universal.” However, as will be discussed in connection with theprober bars 1020 of FIGS. 9 and 13, a fully “universal” prober 1000 maybe provided in which probe heads and connected probe pins may be movedrelative to the bars 1020.

The probe pins 480 are configured to place the frame 410 in electricalcommunication with selected pixels or TFT's(or other devices) formed onthe substrate 150. The probe pins 480 may extend sidewards from theprober bars 420, or may extend below the bars 420. In the arrangement ofFIG. 9, the pins extend downward. However, in the prober arrangement1000 discussed with FIG. 10, the pins 1070 are shown extending to theside for illustration.

The probe pins 480, in turn, are in electrical communication with thecontroller via the frame pins 470 and connected pads 128 As thesubstrate 150 is urged against the prober 400 (shown in FIG. 3),electrical contact between the probe pins 480 and the contact pads (notshown) on the substrate 150 is made. The probe pins 480 are inelectrical communication with the system controller, while the contactpads are in electrical communication with the devices on the substrate150. Consequently, the controller may apply a voltage to a selectedpixel or monitor each pixel for changes in attributes, such as voltage,during testing.

In one test protocol, the substrate 150 is tested by sequentiallyimpinging at least one electron beam emitted from columns 200 (shown inFIG. 3) on discrete portions or pixels composing the thin filmtransistor matrix. After the TFT's are tested, the substrate table 110(with supported plates 120, 130) moves the substrate 150 to anotherdiscrete position within the testing chamber so that another pixel onthe substrate 150 surface may be tested. Additional details concerningelectron beam testing are provided in the referenced '982 PatentApplication. However, it is noted that the present disclosure providesfor a selectively configurable prober 400, rather than a fixed “pictureframe” prober, as disclosed in FIG. 10A of the '982 Patent Application.

FIG. 10 provides a plan view of a prober 1000 in an alternateembodiment. As with prober 400 of FIG. 4, the prober 1000 includes aframe 410. One or more prober bars 1020 is configured to be placedwithin the prober frame 410. The prober bars 1020 are generallydimensioned in accordance with the bars 420 of FIG. 4. In this way, thebars 1020 may be releasably attached to the frame 410.

It can be seen in FIG. 10 that the probe frame 410 defines “x” and “y”axes, and that the prober bars 1020 are oriented along the “y” axes.Thus, the bars serve as “y” bars. However, the prober bars 1020 may alsobe dimensioned to extend along the “x” axis. Alternatively, smallerlength “x” prober bars (not shown in FIG. 10) may be positioned between“y” oriented prober bars.

In the alternate prober embodiment 1000 shown in FIG. 10, one or moreprobe heads are movably mounted on the bars 1020. In one aspect, each ofthe probe heads is “T” shaped so that it may be generically employedalong any axial position along any bar 1020. However, it is preferredthat various configurations for probe heads be employed. In FIG. 10,various probe heads are shown, including “L” shaped probe heads 1022,“T” shaped probe heads 1024, and “+” shaped probe heads 1026. Each ofthe two outer bars 1020 has a pair of “L” shaped probe heads 1022, and apair of inner “T” shaped probe heads 1024. At the same time, there isone, two or more inner probe bars 1020, with each inner prober bar 1020having a pair of “T” shaped probe heads 1024 and a pair of inner “+”shaped probe heads 1026. The “+” shaped heads 1026 are preferably usedin the middle of the glass in the center gap between four displays. The“T” shaped heads 1024 are preferably used between two displays at theglass edge. The “L” shaped heads 1022 are preferably used at a corner ofthe glass. The prober head can be shaped to match the location of thecontact pads 152.

Each of the probe heads 1022, 1024, 1026 includes one or more probe pins1080 which make electrical contact with the substrate (shown at 150 inFIG. 10). More specifically, the probe pins 1080 contact pads 152 (seenin FIG. 11) placed along the substrate 150 for electrical testing. It isagain understood that contact pads 152 are fabricated into the substrate150 at discrete locations to enable display testing. Typically, thesubstrate contact pads 152 are 2 mm×2 mm in cross-section.

The probe heads 1022, 1024, 1026 are preferably fabricated fromaluminum, aluminum oxide, or other nonmagnetic material that canelectrically isolate the probe pins 480. It is desirable to avoidcharging up the heads 1022, 1024,1026 in the event a beam 200 hits ahead.

The bars 1020 are configured to permit the positions of the variousprobe heads 1022, 1024, 1026 to be adjusted along the lengths of thebars 1020. The purpose is to selectively and accurately place the probepins 1080 over the corresponding substrate pads 152 so that electricalcommunication between the prober 1000 and the substrate 150 can beobtained.

In one arrangement, the bars 1020 have guide mechanisms for allowingaxial movement of the probe heads 1022, 1024, 1026. For example, theguide mechanisms may define rails or a guide channel (such as channel432 of FIG. 5) for receiving the probe heads 1022, 1024, 1026. Asecuring mechanism may be used to releasably clamp or fasten the variousprobe heads 1022, 1024, 1026 along the bars 1020. Thus, at thedetermined location where the probe pins 480 lie over the substrate pads(shown at 152 in FIG. 11), the probe heads 1022, 1024, 1026 are lockeddown to fix their position.

It is to be understood that the present disclosure is not limited to themanner in which the probe heads 1022, 1024, 1026 attach to the proberbars 1020. The probe heads 1022, 1024, 1026 may be attached adjacent to,below, or above the prober bars 1020, and may be of any configuration solong as the contact pins 1080 electrically contact the substrate pads152 during testing. The use of probe heads 1022, 1024, 1026 allows forefficient testing of substrates and display sections of different sizes.Further, the use of the outer prober bars 1020 allows the frame 410 tooptionally not include its own probe pins since ideally the outermostcontacts need to be adjustable. It is also understood that the positionof the probe heads 1022,1024, 1026 may be adjusted either manually ormechanically.

FIG. 11 illustrates the prober bars 1020 of FIG. 10 having beenpositioned within a prober frame 410. Here, the prober frame 410 hasbeen placed over a large-area glass substrate 150 for testing. Ofcourse, it is understood that other types of substrates, such as apolymer substrate, may be tested. Four separate prober bars 1020 areshown within the frame 410, dividing the substrate into nine separatepanels 160. Each substrate 150 may include one or more displays 160depending on the end use of the display. Displays may serve as laptopnotebook computer screens, small or large flat screen TV's, cell phonedisplays, or other electronic screens. Anywhere from generally one to 25displays may be formed on a single substrate 150. The probe pins 1080make contact with each display 160 on the substrate 150 during testing.

FIG. 12 shows that the prober bars 1020 and probe heads 1022, 1024, 1026may be reconfigured for different substrate sizes. In this instance,only three prober bars 1020 are employed for display testing. Inaddition, only three probe heads 1022, 1024, 1026 are employed alongeach bar 1020. The extra prober bar 1020 and probe heads 1022, 1024,1026 may be set aside in areas 1021 and 1023, respectively, for lateruse in testing other displays. Areas 1021 and 1023 may thus be reservedwithin the frame 410 for any unused prober bars or probe heads.

FIG. 13 provides a plan view of a prober 1300 in yet an additionalalternate arrangement. Four prober bars 1020 are seen within a proberframe 410. Linear probe heads 1028 are provided along the prober bars1020. The probe heads 1028 are generally “I” shaped, meaning that theyare linear or substantially linear. The “I” probe heads 1028 may also bemixed with “L” shaped probe heads 1022, “T” shaped probe heads 1024, and“+” shaped probe heads 1026 as desired for display testing. Otherwise,with only probe heads 1028, the displays may have pads only on the leftor right sides, but not on the tops or bottoms.

In the prober arrangement 1300 of FIG. 13, the position of the proberheads 1028 may be axially adjusted along the length of the bars 1020.However, it is understood that the axial positions of the prober heads1028 may alternatively be fixed. In order to accommodate displays thathave contact pads of different axial positions, multiple pins 1080 maybe placed along the length of the prober frame. Alternatively, multiplepins 1080 may be placed on various prober heads 1028. In eitherarrangement, the pins 1080 may be selectively pushed down or retractedso that only those pins 1080 in position over the contact pads 152 willcontact the substrate 150 during testing. In this instance, the pins1080 may be pushed down manually, or may be pushed down by a pistonarrangement (not shown) in the test chamber.

Various embodiments of the present invention are provided herein. Forexample, a prober frame 410 is provided of sufficient universal size toaccommodate large area glass substrates of any dimension, such assubstrates having a cross-sectional area greater than 1.5 meters². Whena user is faced with electron beam testing of a substrate having adifferent dimension or a different device layout or having differentdisplay sizes, then the user may adjust the location of the bars 420 or430 without having to purchase an entire new prober. Where additionalbars are needed, then additional bars can be purchased at an expensethat is much less than an entire new prober. Alternatively, bars 1020may be provided that have movable probe heads 1022, 1024, 1026therealong. Alternatively, bars 1020 may be provided that have a fixedlinear probe head 1028 but in which pins along the length of the probehead 1028 may be selectively actuated for contact with correspondingcontact pads 152.

In addition, an electronic devices test system 100 has been described.The test system 100 is used to test electronic devices on a substrate,such as a glass substrate 150. The test system 100 utilizes aconfigurable prober 400 as described above in its various embodiments.The test system 100 includes both the prober 400 and the test systemtable 110. In one aspect, the test system 100 further has one or moreelectron beam columns.

A method for testing electronic devices is also provided. The methodincludes the steps of providing a test system table 110 in a test system100; placing a “y” table 120 on the test system table 110, the “y” table120 being selectively movable along the test system table 110 parallelto a “y” axis; placing an “x” table 130 on the “y” table 120, the “x”table 130 being selectively movable along the “y” table 120 parallel toan “x” axis; placing a configurable prober 400 on the “x” table 130; andplacing a substrate 150 to be tested above the “x” table 130, thesubstrate 150 having contact pads (not visible) and a plurality ofelectronic devices (also not visible) in electrical communication withselected contact pads.

The prober 400 is in accordance with the prober 400 described above, inits various embodiments. Generally, the prober 400 has a frame 410, atleast one prober bar 420 or 430 having a first end and a second end, aframe connection mechanism 412 that allows for ready relocation of theat least one prober bar 420 or 430 to the frame 410 at a selectedcoordinate along the frame 410, and a plurality of pogo pins 480 alongthe at least one prober bar 420 or 430 for placing selected electronicdevices in electrical communication with a system controller duringtesting. In one aspect, the method further includes the step of placingat least some of the plurality of electrical pins 480 in electricalcommunication with the contact pads.

Preferably, the method further includes the step of placing a “z” plate140 on the “x” plate 130. In this arrangement, the substrate 150 isplaced on the “z” plate 140. In one embodiment, the method furtherincludes the step of raising the “z” plate 140 in order to raise thesubstrate 150 to place the pins 480 in electrical communication with thecontact pads. Preferably, the substrate 150 is a glass plate, and eachof the electronic devices is a thin film transistor.

In another aspect of the method, axially adjustable probe heads, e.g.,probe head 1022, may be placed along one or more prober bars 1020.Alternatively, bars 1020 may be provided that have a fixed linear probehead 1028 but in which pins along the length of the probe head 1028 maybe selectively actuated for contact with corresponding contact pads 152.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof. The scope of the inventions isdetermined by the claims that follow.

1. A configurable prober for an electronic devices test system,comprising: a frame; at least one prober bar having a first end and asecond end; a frame connection mechanism that allows for readyrelocation of the at least one prober bar to the frame at a selectedcoordinate along the frame; and a plurality of probe pins along the atleast one prober bar for placing selected electronic devices inelectrical communication with a system controller during testing.
 2. Theconfigurable prober of claim 1, wherein: the electronic devices areplaced on a glass substrate.
 3. The configurable prober of claim 1,wherein: each of the electronic devices is a thin film transistor. 4.The configurable prober of claim 1, wherein: the substrate comprises aglass substrate having contact pads that are in electrical communicationwith selected electronic devices; and selected probe pins contact thesubstrate at selected ones of the contact pads.
 5. The configurableprober of claim 1, wherein: the frame also comprises a plurality ofelectrical probe pins for providing electrical communication between thesubstrate, the prober and the system controller.
 6. The configurableprober of claim 1, wherein: the probe pins are movable along an axiallength of the at least one prober bar.
 7. The configurable prober ofclaim 1, wherein: the probe pins may be selectively pushed down orretracted in order to contact selected contact pads on the substrate. 8.The configurable prober of claim 7, wherein: the probe pins arepositioned onto probe heads fixedly positioned along the length of theone or more prober bars.
 9. The configurable prober of claim 1, wherein:the frame has four sides representing two opposing sides and defining“x” and “y” coordinates; and the frame connection mechanism defines aplurality of holes along an inner surface of the four sides of the framefor receiving the first and second ends of the at least one prober bar,respectively.
 10. The configurable prober of claim 5, wherein: the frameconnection mechanism further comprises an end cap placed along each ofthe first and second ends of the at least one prober bar, with each endcap configured to be received by selected holes of the frame connectionmechanism.
 11. The configurable prober of claim 10, wherein: each endcap is configured to receive a prober bar at more than one laterallocation relative to the selected holes of the frame connectionmechanism.
 12. The configurable prober of claim 1, wherein: the frame isa polygonal frame defining at least “x” and “y” directions; and the atleast one prober bar may be selectively placed on the frame parallel tothe “y” direction and designated as a “y” prober bar, or placed on theframe parallel to the “x” direction and designated as an “x” prober bar.13. The configurable prober of claim 1, wherein: the frame is apolygonal frame defining “x” and “y” directions; and the at least oneprober bar is placed on the frame in the “y” direction and is designatedas a “y” prober bar.
 14. The configurable prober of claim 13, furthercomprising at least one “x” prober bar having a first end and a secondend oriented along the “x” direction, with the first end of each “x”prober bar being releasably connected to the frame, and the second endof the “x” prober bar being releasably connected to one of the at leastone “y” prober bars; and wherein each of the “y” prober bars furthercomprises a bar connection mechanism that allows for ready relocation ofthe at least one “x” prober bar to the “y” prober bar at selected pointsalong the “y” prober bar.
 15. The configurable prober of claim 1,wherein: the electronic devices are placed on a glass substrate thatcomprises a plurality of displays; the at least one prober bar comprisesat least two probe heads, the at least two probe heads being selectivelypositioned and movable along an axial length of the corresponding proberbar; and the at least one prober bar further comprises a plurality ofelectrical probe pins disposed on the at least two probe heads forproviding electrical communication between selected displays, the proberand the system controller.
 16. The configurable prober of claim 15,wherein: at least one of the at least two probe heads is “+” shaped, andis configured to be positioned in the middle of the glass substrate in acenter gap between four displays.
 17. The configurable prober of claim15, wherein: at least one of the at least two probe heads is “T” shaped,and is configured to be positioned between two displays at an edge ofthe glass substrate.
 18. The configurable prober of claim 15, wherein:at least one of the at least two probe heads is “L” shaped, and isconfigured to be positioned at a corner of the glass substrate.
 19. Theconfigurable prober of claim 15, wherein: at least one of the at leasttwo probe heads is “I” shaped, and is configured to be placed betweentwo adjacent displays on the glass substrate.
 20. The configurableprober of claim 1, wherein: the electronic devices are placed on a glasssubstrate that comprises a plurality of displays; the glass substratecomprises at least one contact pad in electrical communication withselected electronic devices; the at least one prober bar comprises atleast two “I” shaped probe heads, fixed along an axial length of thecorresponding prober bar; and the at least one prober bar furthercomprises a plurality of electrical probe pins disposed on the at leasttwo probe heads for providing electrical communication between selectedcontact pads, the prober and the system controller, with the electricalprobe pins being selectively pushed down or retracted to contactcorresponding contact pads on the displays.
 21. A configurable proberfor a thin film transistor (TFT) test system, with TFT devices beingplaced on a large area glass substrate defining multiple displays, theconfigurable prober comprising: a four-sided polygonal frame defining an“x” axis and a “y” axis; at least two prober bars, each having a firstend and a second end, and each being dimensioned to generally match thelength of the “y” axis; a frame connection mechanism that allows forready relocation of each of the prober bars to the frame at selectedpoints along the “x” axis of the frame; and a plurality of electricalprobe pins along each of the at least two prober bars for placingselected electronic devices on the displays in electrical communicationwith a system controller during testing.
 22. The configurable prober ofclaim 21, wherein: each of the at least two prober bars comprises atleast two probe heads, the at least two probe heads being selectivelypositioned and movable along an axial length of the corresponding proberbar; each of the at least two prober heads further comprises a pluralityof electrical probe pins for providing electrical communication betweenselected displays and the system controller; and at least one of the atleast two probe heads is “+” shaped, and is configured to be positionedin the middle of the glass substrate in a center gap between fourdisplays.
 23. The configurable prober of claim 22, wherein: at least oneof the at least two probe heads is “T” shaped, and is configured to bepositioned between two displays at an edge of the glass substrate. 24.The configurable prober of claim 22, wherein: at least one of the atleast two probe heads is “L” shaped, and is configured to be positionedat a corner of the glass substrate.
 25. The configurable prober of claim22, wherein: at least one of the at least two probe heads is “I” shaped,and is configured to be placed between two adjacent displays on theglass substrate.
 26. An electronic devices test system, comprising: atest system table; and a configurable prober, the prober comprising: aframe; at least one prober bar having a first end and a second end; aframe connection mechanism that allows for ready relocation of the atleast one prober bar to the frame at a selected coordinate along theframe; and a plurality of contact pins along the at least one prober barfor placing selected electronic devices in electrical communication witha system controller during testing.
 27. The electronic devices testsystem of claim 26, wherein: the electronic devices are placed on aglass substrate.
 28. The electronic devices test system of claim 26,wherein: each of the electronic devices is a thin film transistor. 29.The electronic devices test system of claim 26, further comprising: oneor more electron beam columns.
 30. A method for testing electronicdevices, comprising: providing a test system table in a test system;placing a “y” table on the test system table, the “y” table beingselectively movable along the test system table parallel to a “y” axis;placing an “x” table on the “y” table, the “x” table being selectivelymovable along the “y” table parallel to an “x” axis; placing aconfigurable prober on the “x” table, the prober having: a frame; atleast one prober bar having a first end and a second end; a frameconnection mechanism that allows for ready relocation of the at leastone prober bar to the frame at a selected coordinate along the frame;and a plurality of electrical probe pins along the at least one proberbar for placing selected electronic devices in electrical communicationwith a system controller during testing; placing a substrate to betested above the “x” table, the substrate having contact pads, and aplurality of electronic devices in electrical communication with thecontact pads; and placing at least some of the plurality of probe pinsin electrical communication with the contact pads.
 31. The method ofclaim 30: further comprising placing a “z” plate on the “x” plate;raising the “z” plate in order to raise the substrate and place the atleast some of the plurality of probe pins in electrical communicationwith the contact pads; and wherein the substrate is placed on the “z”plate.
 32. The method of claim 30, wherein: the substrate is a glassplate; and each of the electronic devices is a thin film transistor. 33.The method of claim 30, further comprising the step of: moving thelocation of the probe pins along an axial length of the at least oneprober bar so as to align the probe pins with selected contact pads. 34.The method of claim 30, further comprising the step of: pushing selectedprobe pins down in order to contact selected contact pads on thesubstrate.
 35. The method of claim 30, further comprising the step of:placing at least two probe heads on the at least one prober bar, each ofthe at least two probe heads supporting the plurality of electricalprobe pins; and re-positioning the probe pins along an axial length ofthe at least one prober bar so as to align the probe pins over selectedcontact pads on the substrate.
 36. The method of claim 35, wherein: atleast one of the at least two probe heads is “+” shaped, and isconfigured to be positioned in the middle of the glass substrate in acenter gap between four displays.
 37. The method of claim 35, wherein:at least one of the at least two probe heads is “T” shaped, and isconfigured to be positioned between two displays at an edge of the glasssubstrate.
 38. The method of claim 35, wherein: at least one of the atleast two probe heads is “L” shaped, and is configured to be positionedat a corner of the glass substrate.
 39. The method of claim 35, wherein:at least one of the at least two probe heads is “I” shaped, and isconfigured to be placed between two adjacent displays on the glasssubstrate.
 40. The method of claim 30, further comprising the steps of:placing at least two “I” shaped probe heads on the at least one proberbar, each of the at least two probe heads supporting the plurality ofelectrical probe pins in a fixed position along the axial length of theprober bar; and pushing selected probe pins downward to contactcorresponding contact pads on the displays.
 41. The method of claim 40,wherein: the substrate is a glass substrate that comprises a pluralityof displays.
 42. A prober bar for an electronic devices test systemhaving a system controller, the prober bar comprising: a first end and asecond end; a plurality of probe pins along an axial length of theprober bar for placing selected electronic devices in electricalcommunication with the system controller during testing; and wherein theprober bar is movably mounted at selected coordinates along a framethrough a frame connection mechanism.
 43. The prober bar of claim 42,wherein: the electronic devices are placed on a glass substrate.
 44. Theprober bar of claim 42, wherein: each of the electronic devices is athin film transistor.
 45. The prober bar of claim 42, wherein: thesubstrate comprises a glass substrate having contact pads that are inelectrical communication with selected electronic devices; and selectedprobe pins contact the substrate at selected ones of the contact pads.46. The prober bar of claim 43, wherein: the probe pins are movablealong an axial length of the at least one prober bar.
 47. The prober barof claim 43, wherein: the probe pins may be selectively pushed down orretracted in order to contact selected contact pads on the substrate.48. The prober bar of claim 47, wherein: the probe pins are positionedonto probe heads fixedly positioned along the length of the one or moreprober bars.